- 學位論文
980nm高功率泵激雷射二極體之研究
Investigation of 980nm High Power Pumping Laser Diodes
摘要
中文摘要 近年來隨著光纖通訊的發展，光放大器扮演著不可獲缺的角色，而其中又以摻鉺之光纖放大器發展較為完全，其優點可歸納為1其光增益與偏振方向無關2同為光纖材料3低雜訊4高的飽和輸出功率等特性，故用於較高增益和最低雜訊特之光放大器最為適合。而泵激雷射在整個光放大器中有著關鍵性光通訊元件之地位，而本研究重點就在於符合市場趨勢之980nm泵激雷射，探討其元件特性。 本實驗從理論分析和實驗印證雙方面著手，從元件的結構磊晶、製程步驟、量測方式、直到結果分析，全都完整呈現，而實驗結果也可發現其內部量子效率、內部損耗、外部量子效應為其高功率之重要成份，在實驗結果方面，為求其內部磊晶品質故做寬面積之雷射，而其功率可達到二百毫瓦以上，進一步，為與光纖耦合之作用做成邊射脊狀雷射，其特性可達到四十六毫瓦在一百毫安培下，若在完成高反射之鍍膜和封裝之後，相信會有更佳的特性表現，另外，本研究也比較不同的結構及不同的材料其特性做為分析以求得其中最佳之條件。
並列摘要
Abstract Recently, the optical amplifiers have played a quite important role during the development of the present fiber-optic communications. In particular, among all optical amplifiers the erbium-doped fiber amplifier (EDFA) has developed more completely and matured for the commercial use. The advantages of EDFA can be listed as follows. 1. the gain of it has no relation to the polarization 2. use the same material as that of fiber 3. low noise 4. high output saturation power. Due to the above advantages, the EDFA has been considered the most suitable optical amplifier for the present optical fiber communications. Otherwise, the pumping laser is the key device for the EDFA system. This study is concentrated on the fabrication of high-power 980-nm pumping lasers, which is expected to meet well with the market’s trend and requirements. This work is carried out from both aspects of theoretical analysis and practical device process. The research contents include the design of device structure, the fabrication process of the device, the measurement of laser characteristics, and finally the analysis of the experimental results, which have been executed sequentially. On the other hand, the internal quantum efficiency, internal loss, and external quantum effects, which are the most important factors to affect the performance of high power laser, are investigated in detail during the evaluation of laser qualities. From this study, we have achieved a broad-area laser with high internal quantum efficiency and low internal loss. In particularly, the power has been possibly to be increased to over 200mW. Further, to couple well with silica optical fiber, another kind of laser, the ridge lasers are fabricated and the output power are typically about 46mW under an injection current of 100mA. In conclusion, it has been found from the present work the optimal conditions for both broad-area type and a ridge type laser diodes with the different materials and structures. Besides, it is possible to further elevate the laser qualities by using high-reflection faceting coating and p-size down package techniques. Both techniques can suppress the problems of Joule-heat to a great degree. The effect is very important when the operation of high-power laser is under consideration since a high injection current is necessary in that case. However, the optimal conditions for the above techniques are still not clarified and needed to be determined in the following work.